A door device of the present invention is associated with a long double-opening door for vehicles, particularly for coupes, singly covering a range of a vehicle including two rows of front and rear seats in the longitudinal direction of the vehicle, which door allows rear-seat occupants to get out the vehicle while front-seat occupants are seated.
Of the vehicles manufactured and marketed, no vehicle has a double-opening door on the side faces of the vehicle body.
However, some patent registrations can be found regarding a double-opening door provided on the side faces of a vehicle. Let us discuss these patented double-opening doors. Patent Documents 1, 2 and 3 each deal with a technique concerning double-opening door of a normal length and the technique does not enable a rear-seat occupant to get off the vehicle while a front-seat occupant is seated.    Patent Document 1: JP-A-S58-101980    Patent Document 2: JP-A-S58-191881    Patent Document 3: JP-A-S63-284383
A long double-opening door for vehicles has three issues that have to be solved. The first issue is the rigidity against a stress, such as a wind pressure, imposed on a vehicle body in its horizontal direction when the door is opened. The second issue is the rigidity against a stress, such as the weight of a person, imposed on a vehicle body in its vertical direction when the door is opened. The third issue is the rigidity, during traveling, of the vehicle body that has a large opening to be used for the long double-opening door.
The inventor of the present invention made an invention related to a long double-opening door for vehicles, which is disclosed in Patent Document 4. Patent Document 4 deals with a technique for solving the three issues.
With the technique of Patent Document 4, when a front-seat occupant gets in/out the vehicle, a first opening/closing means provided at a front end portion of the door is released and the door is supported by a first opening/closing means (connecting means) provided at a rear end portion of the door and a second opening/closing means (connecting means) provided at a center portion of the door, in a manner of enabling opening/closing of the door. Further, when a rear-seat occupant gets in/out the vehicle, the first opening/closing means provided at a rear end portion of the door is released and the door is supported by the first opening/closing means (connecting means) provided at a front end portion of the door and the second opening/closing means (connecting means) provided at the center portion of the door, in a manner of enabling opening/closing of the door.
However, the technique of Patent Document 4 raises a fourth issue. Specifically, due to the second opening/closing member (connecting means) located at the center portion of the door, when the front-seat occupant and the rear-seat occupant get in/out the vehicle, the door has to be necessarily closed once, after either of the front-seat occupant or the rear-seat occupant has got in/out the vehicle. Otherwise, the other of the front-seat occupant or the rear-seat occupant cannot get in/out the vehicle.    Patent Document: JP-A-2007-324266